Disintegrating test ammunition



May 30, 1961 R. M. FERGUSON DISINTEGRATING TEST AMMUNITION Filed Aug.31, 1959 INVENTOR. RALPH M. FERGUSON ATTORNE ate DISINTEGRATING TESTAlVIlVIUNITION Ralph M. Ferguson, Dayton, Ohio, assignor to the UnitedStates of America as represented by the Secretary of the Air Force Theinvention described herein may be manufactured and used by or for theUnited States Government for governmental purposes without payment to meof any royalty thereon.

This invention relates to disintegrating test ammunition for use in alltypes of gun function testing except those in which target firing ofother tests requiring accuracy are involved. More particularly thepresent invention relates to the construction of the bullet or slugemployed in the disintegrating test ammunition.

An object of the present invention is to provide test ammunition whichwill disintegrate within one hundred yards of the weapon being tested. Afurther object of the invention is to eliminate the necessity forconstructing expensive firing butts, wide angle and all angle ranges inorder to test fire control systems of machine guns and cannons includingthe accessories thereto such as solenoids, boosters, heaters andcharges.

A still further object of the present invention is to providedisintegrating test ammunition which, when fired, will produce identicalforces on the structure of the aircraft, gun mounts and other parts ofthe mounting structure as is produced by standard ball or test typeammunition.

The disintegrating projectile of the present invention comprises a thinbullet-shaped outer shell of low melting point metal, weighting meanswithin said thin outer shell, said weighting means being disposed withina substantially conically-shaped paper container, air space separatingsaid thin outer shell from said paper container, holding means adjacentboth the front and rear ends of said paper container to maintain saidpaper container in a stationary relationship with said thin outer shell,and means sealing said weighting means within said paper container andsaid paper container within said thin outer shell.

These and other objects and features of the present invention aredescribed below in connection with the accompanying drawings.

In the drawings:

Fig. l is an end view of the bullet or slug of the present invention;

Fig. 2 is a sectional view of the bullet or slug of the presentinvention taken along the line 2-2 of Fig. 1.

Referring now in detail to the drawings wherein like reference numeralsdesignate like parts and most particularly to Fig. 2 there is shown thebullet-shaped projectile of the present invention hereinafter referredto as the slug and generally designated 20.

The outer periphery of the slug 20 is formed by a thin metal shell 22 ofapproximately 3/64 of an inch in thickness having one end open as at 24.A driving band 26 is formed integral with said thin metal shell near theopen end 24 of the slug, said driving band 26 has a shoulder 28positioned to abut the front edge of a charge containing cartridgecasing (not shown). An annular depression 30 is located in said thinmetal shell midway between the shoulder 28 and the open end 24 formingan annular stop 32 on the inner surface of the thin metal shell 22.

A thin-walled substantially conically-shaped paper conato 2 ,986,091Patented May 30, 1961 tainer 34 having a radially-flared flange portion36 at its open end 38 is maintained in stationary spaced relation to theouter shell by means of a wad of wax (or pitch) 40 located in the noseof the outer metal shell and the abutment of the outer surfaces of theflange portion 36 with the inner surface of the outer shell and theannular stop 32.

The abutting engagement of the flange portion 36 and the annular stop 32further restricts the entry of the paper cone 34 into the outer shell 22thus maintaining the paper cone, with the aid of the Wax wad 40 and theslug sealing means 44 (later to be described), in a fixed positionwithin the outer shell of the slug.

The paper cone 34 is filled with loose material 42 which may be any of anumber of weighting materials such as powdered lead, lead shot or leadfragments. The weighting material 42 is sealed within the paper cone 34and said paper cone is sealed within the outer metal shell 22 by a waxplug 44. Pitch or a felt wad would also adequately perform the scalingfunction of the plug 44 but wax is believed to be the most satisfactorysealing media for the intended purpose of the plug 44 as presentlyunderstood.

The weight-producing material 42 is necessary to the proper functioningof the test ammunition since the weight of the test ammunition must bethe same as an actual round to produce identical recoil and shockcharacteristics on the weapon being fired.

In operation, the preferred embodiment of the present invention willcomprise a thin outer shell 22, 3/64 of an inch thick, and constructedin the form of a casted alloy shell consisting of 50% bismuth, 25% lead,Il /2% tin and 12 /2% cadmium which will have a melting point ofapproximately 149 F. It should be understood that the outer shell 22could be formed of other low melting point alloys but the abovedisclosed alloy is exceptionally well suited for the purpose of thepresent invention and is preferred. When the slug 20 is fired a thrustof approximately 6,500 psi. is exerted thereon. The heat of theexploding charge and barrel friction will cause the thin outer shell 22of the slug 20 to be heated to a temperature near its melting point thusreducing the outer shell 12 to putty-like consistency. Substantially allof the heat generated by the firing of the slug will be retained by thethin outer shell 22 because of the air space 46 separating said thinouter shell from the weighting material 42. As the slug leaves the gunbarrel it will be subjected to approximately 600 psi. of pressure andair friction which will complete the destruction of the thin outer shell22. The magnitude of the pressures of thrust, outside air pressure andfriction will be more than enough to tear apart the now exposed papercone 34, thus permitting the lead shot or other weight-producingmaterial 42 to be scattered over a relatively small area not exceedingyards from the barrel of the weapon.

The present invention has been described in detail above for the purposeof illustration only and is not intended to be limited by thisdescription or otherwise except as defined in the appended claims.

I claim:

1. A disintegrating projectile of the type described comprising a thinbullet-shaped outer shell of low melting point metal having one endthereof open, Weighting means within said thin outer shell, asubstantially conicallyshaped paper container disposed between saidouter shell and said weighting means, one end of said paper containerbeing open, said paper container being separated from said thin outershell by an air space, holding means adjacent both the front and rearends of said paper container to maintain said paper container in a fixedposition within said outer shell, and sealing means closing the openends of both said outer shell and said paper container.

2. A disintegrating projectile of the type described comprising a thinouter metal shell of approximately of an inch in thickness, said metalshell adapted to melt when said projectile is fired, a substantiallyconicallyshaped paper container having a radially-flared flange portionadjacent the base thereof disposed within said metal shell, said papercontainer being separated from said metal shell by an air space, anannular ring on the inner surface of said outer metal shell positionedto abut said radiallyflared flange portion to limit the entry of saidpaper con- 'tainer into said outer metal shell, a wax wad positionedwithin the nose of said outer metal shell and acting in conjunction withsaid radially-flared flange portion to hold said paper containerstationary within said outer metal shell, lead shot disposed within saidpaper container to approximate the Weight of a standard round, and meanssealing said lead shot within said paper container and said papercontainer within said outer metal shell.

3. A disintegrating projectile according to claim 2 wherein said thinouter metal shell is constructed of a cast alloy of 50% bismuth, 25%lead, 12 tin and 12 /2 cadmium.

4. A disintegrating projectile of the type described comprising abullet-shaped thin outer metal shell having the trailing end thereofopen, said metal shell consisting of an alloy of 50% bismuth, 25% lead,12 /z% tin and 12 /2'% cadmium and being approximately of an inch thick,a paper container disposed within said metal shell, said paper containerbeing separated from said metal shell by an air space, means within saidpaper container to provide the projectile with accurate weight,additional means 4 sealing said first named means within said papercontainer and closing the open end of said metal shell.

5. A disintegrating projectile of the type described comprising abullet-shaped thin outer metal shell having the trailing end thereofopen, said metal shell consisting of a cast alloy of 50% bismuth, 25%lead, l2 /z% tin and 12 /z% cadmium and being approximately of an inchthick, a substantially conically-shaped paper container having aradially-flared flange portion adjacent its open trailing edge disposedwithin said metal shell, said paper container being separated from saidmetal shell by an air space, an annular stop on the inner surface ofsaid metal shell near the open end thereof, a wax wad positioned in thenose of said metal shell acting in conjunction with the abutment of saidradially-flared flange and said annular stop to maintain said papercontainer in a fixed stationary relationship with said metal shell, leadshot disposed within said paper container, a wax plug sealing said leadshot within said paper container and said paper container with in saidthin outer metal shell.

References Cited in the file of this patent UNITED STATES PATENTS1,877,773 Minto Sept. 20, 1932 FOREIGN PATENTS 215,008 Great BritainJan. 8, 1925 OTHER REFERENCES Mark s Handbook, third edition, secondimpression, 1930. Published by McGraw-Hill Book Company, Inc. Copy inDiv. 10, page 673.

